TY - JOUR
T1 - CHIP regulates aquaporin-2 quality control and body water homeostasis
AU - Wu, Qi
AU - Moeller, Hanne B.
AU - Stevens, Donté A.
AU - Sanchez-Hodge, Rebekah
AU - Childers, Gabrielle
AU - Kortenoeven, Marleen L.A.
AU - Cheng, Lei
AU - Rosenbaek, Lena L.
AU - Rubel, Carrie
AU - Patterson, Cam
AU - Pisitkun, Trairak
AU - Schisler, Jonathan C.
AU - Fenton, Robert A.
PY - 2018
Y1 - 2018
N2 - The importance of the kidney distal convoluted tubule (DCT) and cortical collecting duct (CCD) is highlighted by various water and electrolyte disorders that arise when the unique transport properties of these segments are disturbed. Despite this critical role, little is known about which proteins have a regulatory role in these cells and how these cells can be regulated by individual physiologic stimuli. By combining proteomics, bioinformatics, and cell biology approaches,we found that the E3 ubiquitin ligase CHIP is highly expressed throughout the collecting duct; is modulated in abundance by vasopressin; interacts with aquaporin-2 (AQP2), Hsp70, and Hsc70; and can directly ubiquitylate the water channel AQP2 in vitro. shRNA knockdown of CHIP in CCD cells increased AQP2 protein t1/2 and reduced AQP2 ubiquitylation, resulting in greater levels of AQP2 andphosphorylatedAQP2.CHIP knockdown increased the plasma membrane abundance of AQP2 in these cells. Compared with wild-type controls, CHIP knockout mice or novel CRISPR/Cas9 mice without CHIPE3 ligase activity had greater AQP2 abundance and altered renal water handling, with decreased water intake and urine volume, alongside higher urine osmolality. We did not observe significant changes in other water- or sodium-transporting proteins in the gene-modified mice. In summary, these results suggest that CHIP regulates AQP2 and subsequently, renal water handling.
AB - The importance of the kidney distal convoluted tubule (DCT) and cortical collecting duct (CCD) is highlighted by various water and electrolyte disorders that arise when the unique transport properties of these segments are disturbed. Despite this critical role, little is known about which proteins have a regulatory role in these cells and how these cells can be regulated by individual physiologic stimuli. By combining proteomics, bioinformatics, and cell biology approaches,we found that the E3 ubiquitin ligase CHIP is highly expressed throughout the collecting duct; is modulated in abundance by vasopressin; interacts with aquaporin-2 (AQP2), Hsp70, and Hsc70; and can directly ubiquitylate the water channel AQP2 in vitro. shRNA knockdown of CHIP in CCD cells increased AQP2 protein t1/2 and reduced AQP2 ubiquitylation, resulting in greater levels of AQP2 andphosphorylatedAQP2.CHIP knockdown increased the plasma membrane abundance of AQP2 in these cells. Compared with wild-type controls, CHIP knockout mice or novel CRISPR/Cas9 mice without CHIPE3 ligase activity had greater AQP2 abundance and altered renal water handling, with decreased water intake and urine volume, alongside higher urine osmolality. We did not observe significant changes in other water- or sodium-transporting proteins in the gene-modified mice. In summary, these results suggest that CHIP regulates AQP2 and subsequently, renal water handling.
U2 - 10.1681/ASN.2017050526
DO - 10.1681/ASN.2017050526
M3 - Journal article
C2 - 29242247
AN - SCOPUS:85042710807
SN - 1046-6673
VL - 29
SP - 936
EP - 948
JO - Journal of the American Society of Nephrology : JASN
JF - Journal of the American Society of Nephrology : JASN
IS - 3
ER -